Accurate computation of X-ray absorption spectra with ionization potential optimized global hybrid functional

作者：Jin Yifan^*; Bartlett Rodney J

来源：Journal of Chemical Physics, 2018, 149(6): 064111.

DOI：10.1063/1.5038434

This manuscript presents the first consistent ionization potential (IP) optimized global hybrid functional to accurately estimate the vertical ionization and excitation energies of the inner-shell electrons in molecules. The new method fulfills the IP theorem that the Kohn-Sham eigenvalues of all the occupied orbitals (including the core orbitals) are good approximations to the exact vertical ionization energies. The accuracy of the one-particle spectrum is essential to enabling the one-particle density functional theory (DFT) to provide accurate results. Compared to its precursor, the range-separated hybrid functional CAM-QTP00, the new method is more computationally efficient. The IP theorem enables the new method to provide inner-shell ionization energies measured by X-ray photoelectron spectroscopy, and it can further accurately simulate the X-ray absorption spectrum (XAS, or NEX-AFS). The simulated spectra can be compared to the experiment directly without shifting. In addition, the new method reduces the delocalization error (many-electron self-interaction error) which is a severe problem in DFT. Published by AIP Publishing.

• 出版日期2018-8-14